Anthony Edwards Dr. Mark Greene Actor Eriq La Salle Dr. Peter Benton Actor Noah Wyle Dr. John Carter Actor Julianna Margulies Head Nurse Carol Hathaway Actor Gloria Reuben Jeanie Boulet Actor Laura Innes Dr. Kerry Weaver Actor Alex Kingston Dr. Elizabeth Corday Actor Kellie Martin Lucy Knight Actor Goran Visnjic Dr. Luka Kovac Actor Michael Michele Cleo Finch Actor Maura Tierney Abby Lockhart Actor Ming-Na Wen Actor Paul McCrane Robert Romano Actor Myndy Crist Valerie Page Guest Star Peg Phillips Mrs. Duffy Guest Star Diane Baker Louise Duffy Guest Star John Cullum David Greene Guest Star Louis Ferreira Michael Mueller Guest Star Hank Stratton Curt Oberg Guest Star Lawrence Monoson Dean Rollins Guest Star Andre Kinney Trevor Guest Star Ellen Crawford Nurse Lydia Wright Guest Star Bellina Logan Nurse Kit Guest Star George Clooney Actor Michael Crichton Executive Producer John Wells Executive Producer